William d



(No Model.)

W. D. PATTERSON.

TELEMET'ER.

Patented June 12, 1883.

to be afull, clear,

FFlC,

\VIL'LIAM' D. PATTERSON, OF SAN 1 P&N(IS(.O, (ALTFORNL-X.

TELEMETER.

BPECIFIOATION forming arrot" Letters.IPatent No. 279,273, dated June 12, 1883.

' Application mm March a, less. (No model.)

To all whom it may concern:

Be it known that I, WILrL-ua 1). DarrensoN, of the city and county of San Francisco, State of California, have invented an Improved Teleineter; and I hereby declare the following and exact. descri ption thereof.

My im'ention relates to a new and useful teleineter; and it consists in a tube having a means at one end for observing the directand reflected ray of light from the object, and a means at the other end for eausi ng the. reflected ray to coincide with the direct ray, and for reading the angle of the reflected ray, where by, saidangle, the base, and the right an gle of the direct ray with the line of colli1uation in the tube being known, the sine of the angle of the reflected ray may be readily computed and the distance of the object ascertained.

The object of my invention is to ascertain the linear distance to any given object, and to provide for this purpose a simple andet't'ect ive instrument, as will hereinafter particularly appear, reference being made tothe accompanying drawings, in whiehlliigure 1 is a horizontal. longitudinal sect ion of my telemeter. Fig. 2 is a vertical longi tudinal sect-ion, showing screw-flanges l. and (l on the tube A.

A is a tube, having in one end asilvered rellector, B, adapted to change its inclination on pivot 11.

(.3 is an arm extending through a slot in the tube, and secured to the back of the reflector, whereby said reflector may be moved. 'lhis arm carries a vernier, c, adapted to travel over a graduated arc, 1'), divided to read angles to 5, or t-lwreabout.

la the tube A, opposite the .retleclor, is an objeet'glass, E. lln the other end of the tube A is a reflector, B, and another, B, and a third, l3, all stationary and set at angles of lorty-lire degrees inthetube, butat right angles with each -other. The one marked B is but. one-halt silvered, its upper portion being transparent. In front of this, inth'etube, is an 1 object-glass, E, and behind it, in thetube, is

inserted alsmall telescope, u, the line of collimation of which is at right angles with the line of collimation ol' the tube A.

Upon the center of the tube is termed a i be readily calculated. pass ll aeeurat e bearings may be taken.

screw-flange, (l, for the reception ol'any suitable t'orm ofstand or tripod. On top is formed asimilarscrew-flange, l, upon which is screwed a compass, H.

The use of this telemet er is as follows: it is so platted that the line of collimation through the simtlltelescope and the object-glass E shall be in direct line with an object, the ray of light from which thus 't-lnrms a right angle with the line of collimatitm of the tube A. This direct ray is observed through the hal t-silvered glass l1 and the small telescope u. from the said object before observed, entering object-glass l ),is caught on the pivoted retlieel or B. From this it is reflect ed through the length of the tube to stationary reflector ll, thenceto reflector B" and to the silvered portion of 1 from whence it is thrown down to the eye at the small telescope. Now, on account at the parallax caused by the length ol'the tubeA as a base, this ray of reflected light will not be parallel with the direct ray oflight from said object observed through the obiect-gh 's 1*), the transparent port ion of the retleclorili, and the small telescope u; 'lhe arm t, traveling on the graduated are, is now moved to change the inclination of the reflector 15 until the two rays of light from said object coincide in. the one-halt-silvered glass 1 and form one image.

A ray of light The vernier 0 indicates on the graduated arr I) the true angle at which. lhe. ray strikes the reflector l2. This angle, the length of the tube.

A as a base, and the right angle formed by the direetray with the line of collimation of tube A being (HUWII, the distance ol'the object may By the aid ol'the com- A printed scale ot' distances correspomling to observed angle may accompany the instru .ment.

llavingthus described my invent ion, whatl claim as new, and desire to secure by lielters vPatent, is

1. in a teleineler, the tube A, having an objectg ass at each end, and a small telescope, yr. whose collimaled line is at right angles with the eollimated lineol'said tube, and adapted to permitol. servation in allirwt line through one of the. object-glasses, in combination with a swinging mirror or relleelor within thet-ube A in line with the other object glass, a means IOU ' for moving and. reading the inclination of said mirronand a-system of reflectors in the other 7 end of-the tube to reflect the ray of light from the swinging mirror to coincide with the di- 5' rect ray, substantially as herein described.

2; In ate1emete1,-t-he tube A, having an obj eetglass at each end, and a small telescope whose line of collimation is at right angles with the collimated line of tube A and in line with [O the object-glass at one end, in combination With the reflectors B B. and the half-silvered,

reflector or-glass B arranged, as shown, to transmit the direct ray to the eye at the small. telescope, the swinging mirror or refleetorB 15 at the other end of the tube A, adapted to rei ceive a ray through the objectrglass at that 1 end, a means for-moving or ehanging'theinclination of said reflectorto eauselits ray to coincide with the direct my at the other end,- and a means for, reading the inclination of 20- .for/inclining and reading the inclination of said mirror, consisting of the arm Q, the Vernier c, and the graduated are D, all arranged and operating substantially as herein described.

In witness whereof I hereunto set my hand.

WILLIAM DJPATTE RSON.

Witnesses: WM. F. Boom, J. H. BLOOD. 

